Refactor: Changes remaining time variable type from int to chrono
Summary:
This is a partial backport of core#23832
https://github.com/bitcoin/bitcoin/pull/23832/commits/6111b0d7fac89b7a0a03284ca6ec030ca7f30b99
Depends on D13374
Test Plan: ninja all check-all
Reviewers: #bitcoin_abc, sdulfari
Reviewed By: #bitcoin_abc, sdulfari
Differential Revision: https://reviews.bitcoinabc.org/D13375